​Q: I'm brewing a blonde ale, all grain. I used Crystal hops for the 40 min, 20 min, and the last 5 min boil. Should I continue using Crystal hops for dry hopping? Or should I use Cascade hops, or a mix of both?

A: For dry hopping, any of the three options are acceptable depending on what aroma/flavor attributes you desire in the beer. Crystal will contribute a spicy, flowery, slightly citrus aroma. Cascade will contribute a flowery or citrus (grapefruit) aroma. Most brewers have found that using a blend of hop varieties for dry hopping offers more depth and complexity in addition to increased flexibility due to supply and availability issues.

Q: I'm looking at initiating a can conditioning program. We are planning on filling the beer cold (~32–34°F). I will need to warm it up from the filling temperature to 65–70°F in order to initiate conditioning fermentation in the can. I need to calculate how long it will take to warm it through a "warming tunnel" given the ΔT and the temperature of the water used to warm it (~125°F). The can volume is 16 oz., so how much residence time will be needed to get the beer into the desired temperature range?

Also, if we wanted to build a warming table—i.e., an accumulation table that could hold an inventory of cans that slowly move under a hot water shower—how do I calculate how big to make it if I am running at 45 cpm and need a residence time of X (from the calculation above) to warm the beer properly?

A: Why don't you consider putting in a beer warmer so beer is instantaneously warmed to 64–68°F? I recall one particular brewery that looked at a "warming tunnel" but didn't like how high the temperature of the water needed to be (125°F) or how difficult it was to control the beer temperature. It seemed that to get the interior core of the beer up to 65–70°F, the beer next to the can wall would get close to the temperature of the water, possibly harming or autolyzing the yeast. Their current beer warmer is programmed so that if the water temperature goes above 77°F, the beer flow stops and the unit goes into recirculation to avoid "cooking" the beer.

A: Dynamic low-pressure boiling uses a temperature range of 100–103°C for wort
boiling. Necessary parameters of wort boiling, such as the stripping of
dimethyl sulfide (DMS), can be widely influenced by a number of factors
including the number of pressure build-up intervals, the intensity of the
pressure, and the rate of alteration of the pressure (Δp/ΔT). With all these
factors in mind, total evaporation can be reduced to 4–5%. In this case,
boiling and DMS reduction can be done in 60 minutes.

​Q: Is pectin build-up a problem for kegs or bottle fillers used to package cider?

A: Pectin is found in fruits where it is part of the cell wall material. It is a complex polysaccaride and forms a jell. There is very little available data on how to deal with pectin build-up on filling equipment in packaged cider, however many cider makers will use a pectinase enzyme to break it down and eliminate it from being a problem. For cider makers who do not treat the pectin with an enzyme and package unfiltered product pectin build up can be an issue in both kegs and fillers. I asked Joe Dirkson (Ecolab) and Dana Johnson (Birko) to weigh in on this. Their consensus is to use a heavier caustic concnetration (up to 4%) with an oxidizer additive to help break up the pectin. They both preferred a hydrogen peroxide additive. The additive has a short life in the caustic and must be injected in small amounts at regular increments to be effective and to keep a concentration between 1000-5000 ppm.

​Q: In Volume I of the MBAA Practical Handbook for the Specialty Brewer, in the hops section, it was stated that freshly harvested hops should be aged for a minimum of 6-12 months before using. This caught me by surprise. I would have figured fresher the better. Really?

A: For some hops, particularly low alpha aroma varieties, the slow oxidation that occurs in baled whole hops kept at freezing storage temperatures (below 0 degrees C) over the course of several months will develop, improve and stabilize their flavors. This is due to the oxidation of certain compounds called sesquiterpenes. The oxidized sesquiterpenes develop complex flavors. However over aging the hops can also produce a harsh bitter quality and cheesy aromas. Most brewers are using pelleted hops so any request for aging would have to be made to the supplier and specified because once pelleted and packed into nitrogen flushed bags, the oxidation process is almost completely shut down.

Q: Awhile back I noticed the TTB approval of Dimethyl Dicarbonate (DMDC) as a processing aid in beer production, but I haven't seen anything more written about it. Can you tell me a little about this option? The TTB release describes it as a "microbial load reducer" and I can find a number of resources that cite its use in winemaking. They seem to use it to reduce wild yeasts. Does DMDC have any effect on beer-spoiling bacteria? Is this a product we'll see beer suppliers carrying in the near future? An overview of processing instructions or help identifying further resources might be useful as well.

A: The commercial name is Velcorin and it has been used in soft drinks and wines (usually low alcohol sweet wines with some residual sugars) for some time, mostly in South America and South Africa. It has recently been approved for use in both wine and beer in the US and at least one large US winery is studying its use in sweet, low alcohol wines. Velcorin is effective against yeast, bacteria and molds. It penetrates the cell membrane and targets certain enzymes which results in the cells lysing (opening up) and re-fermentation is almost impossible. You can find out more at www.velcorin.com.

​Q: You had mentioned that you had some experience with reclaiming bottle rinse water and sending it through the filler vacuum pump and possibly into a pasteurizer. Do you recall if there was any filtration of the water? Was there some sort of a storage tank for the water? We really see this as a great opportunity with 3 bottling lines and 2 can lines and any insight would be GREATLY appreciated.

A: The rinse water recovery is low hanging fruit but will need a receiver tank, float control for fresh water refill and a pump. We let the water from the rinser fall by gravity into a receiver tank and then pumped that water through the vacuum pump to cool the seal. If the water level got low (rinser had shut off) then the float would open a fresh water valve and keep the tank full so the seal would not run dry and overheat. We then would collect the water out of the vacuum pump and into another receiver and pump that water (now slightly warm) to shower off bottles coming off the crowner. The shower water would go to drain. This way we used the water 3 times and saved an appreciable amount off the water and sewer bills. You could use the water out of the vacuum pump in a pasteurizer as well.

​Q: I just read your article on building a brewery floor. My Husband is a brewer, looking for a commercial spot to set up shop. However, all the warehouses we have looked at do not have a floor drain. I know we will have to install a pad and somehow create a slope going in to a drain. Do you know of any other type of set up (other than breaking the concrete) and/or material to create the pad? Many property owners do not like the idea of concrete and would rather we bring in a different (hopefully portable) material.

A: To make beer you will need some kind of floor drain system. Some people use berms and then wet the floor down to see its natural low spot and that is where the drain goes. However this cheap and cheerful method results in the same concrete cutting to install the drain and piping as a proper system and requires a squeegee and lots of effort to actually use. Not recommended! The options for you to install a properly drainable floor, ie one that works, are the following:

• Take out the floor and pour new slab with proper re-bar reinforcement after installing trench drains and drain piping. Slope at ¼-5/16” per foot to the drains then seal with epoxy type mortar• Pour a topping slab over the existing concrete floor (if it can take the weight load of your equipment), with same slope and sealing as above suggestion• Use a grout system and hardened tiles to the trench drains using the same kind of slope

Sorry but unfortunately there no portable/temporary systems out there (yet).

A: bottle conditioned beers can have 0.5 million cells per ml or more to complete the bottle fermentation and carbonate the beer. If the beers after bottling are subjected to higher temperatures in storage then they can develop meaty-brothy flavors.

​Q: We are having some debate as to passivisation techniques, so I was hoping you could shed some light on what is best practise. In particular, could you clarify the different methods of passivisation in terms of chemicals used (and at what concentrations), time, temperature, and whether or not rinsing is desirable?

A: There is no definitive answer to this question but the main objective to passivation of stainless steel tanks and vessels is to eliminate tramp iron deposits and establish a layer of protective chromium oxide to resist corrosion. I have asked two experts with a lot of experience in this area, Joe Dirkson of EcoLab and Ashton Lewis of the Paul Mueller Company to comment.

Joe's response is based on the traditional method of passivation involving a strong oxidizing Nitric acid solution:

Stainless steel derives its corrosion resistance from a very thin layer of chromium oxide that forms at the metal surface when exposed to oxygen in the air. The chromium oxide film can form in air if the stainless steel is clean and dry. So the passivation process is really about making sure that all contaminants are removed from the surface, then allowing the surface to dry, so that the passive layer can form.

New vessels and piping may have a variety of soils, including polishing oil, EP (extreme pressure) additive oils, adhesive film and tramp iron (polishing dust). All of these soils must be completely removed.

The following steps are recommended for effective passivation. High chemical concentrations are required - consult the Safety Data Sheet prior to chemical use. Be sure to wear appropriate PPE.

1. Inspect the metal surfaces for any soil, film, deposits or extraneous material. Use a flashlight. A digital camera is helpful to document the surface appearance.2. Check with the equipment supplier to determine if the manufacturer/supplier has any special restrictions or cautions about passivation – want to be sure to not invalidate the equipment manufacturer’s warranty. 3. Assuming a CIP system is available, rinse the tank with water. Note, avoid water that has a high (greater than about 50-75 ppm) chloride ion content. High chloride content can lead to pitting corrosion.4. Wash the tank with a strong caustic solution. Some caustic products are specially formulated for washing new tanks – check with your chemical supplier about specific products. Circulate for one hour at 140-150F.5. Rinse the tank with water until neutral. Observe sheeting action during the rinse. If the tank is satisfactorily clean, the rinse water should sheet over the surface. Any streaking or spots indicates incomplete cleaning. Burst rinsing is recommended.6. Repeat the caustic clean as necessary.7. Wipe the surface with a soft white cloth. Inspect for any particles or brown film. Brown film can be either tramp iron dust (polishing dust) or oil. Polishing dust can be confirmed by holding a lab magnet onto the dry cloth – iron particles will adhere to the magnet. .8. To remove tramp iron dust, first the surface should be washed with a cationic detergent to minimize static charge. Apply a cationic detergent by foam or CIP. Brush wash if necessary. Rinse.9. Circulate a strong nitric acid solution for one hour at 140-150F. A concentration of 10-20% active nitric acid by weight is recommended to dissolve all tramp iron. Note, nitric acid is significantly more effective than citric acid in terms of dissolving tramp iron. Excercise extreme caution with this strong acid solution!10. Rinse. Repeat the white cloth test to validate that all tramp iron has been removed. Repeat the acid wash as necessary.11. Allow the surface to dry completely. Dry time can vary depending on temperature, and air exposure. For pipes and surfaces that are not readily exposed to air, 72-hour dry time is recommended.12. Prior to equipment startup, run a normal CIP cycle and sanitize.

Ashton's response is based on a less aggressive solution of Citric acid incorporated with EDTA:

The old stand by method is to use hot, highly concentrated nitric acid. Nitric is a strong oxidizing acid capable of dissolving iron from the surface of stainless steel alloys. Since it is a strong oxidizer it also actively forms a very thin layer of chromium oxide; this is the "passive" layer that protects stainless steel alloys from corrosion.

The problems with this method are numerous: this can be dangerous to personnel, it can damage elastomers and it is problematic for disposal to municipal wastewater systems. I was on a start-up of a pasteurizer at a large rum producer's facility and an outside chemical contractor came in to passivate the equipment we installed. They insisted on using 50% nitric acid heated to 160F for the operation. I was extremely nervous for the entire operation. This person then insisted on dumping the solution after each use and this turned out to cause some problems with the plant's effluent treatment system. We have pharmaceutical customers who use this method and they change out ALL of the elastomers in their system after passivation. In a large process module this is an expensive and time-consuming endeavor.

An alternate method is to use a citric acid solution that has been pH adjusted and enriched with EDTA. Citric acid forms a complex with free iron and is an effective and safe method to perform the first step of passivation. At Mueller, we use the citric acid method because the nitric acid method is simply too dangerous. Years ago I was discussing this topic with someone at a major global brewer and learned that they also have an approved citric acid method. Talk to your chemical supplier about options using a citric acid/EDTA solution.

With any new cleaning/passivation method it is very important to test the methodology on a small sample of equipment to verify that the procedure does not damage equipment. I do not mean to suggest that 50% hot nitric used on Type 304 stainless needs to be tested before use, but if a solution with some unknown additives is applied to "stainless steel" with unknown alloy composition the user should really do some testing before exposing a whole new tank to the method. I have heard some unpleasant stories about foreign steel with unknown composition being damaged during cleaning.

Q: We produce 7,000bbls/year all draft. We cannot explain to the owner why we should or should not filter our beer into package except that "cause everyone does." We currently only have a plate and frame filter. It is terrible and we find it strips flavor of our hoppy products, and we are a American craft brewery... everything is hoppy. So I guess my question is why should we filter?! I know about colloid stability. Our package shouldn't be sitting on shelves long because its only going 20 miles, I'm not to worried about that. What else do I need to be worried about? Our beers drop clear. Yes its not totally brilliant, but that is also something we don't really care about. In summary is there anything you can add or give insight to about rationales about filtration into package?

A: Filtration is not a requirement for bottled or canned beers but keep in mind that even beer shipped only 20 miles away will probably end up sitting out at room temperature were yeast and sediments forming in the beer might form meaty-bready flavors which may not impress your customers. The answer to your question of whether to filter or not depends entirely with what you want your customers to experience. Some beer styles are meant to have a haze, i.e. hefe-wizen, Saison and many IPA's are sold with a hazy golden hue that "glows in the glass." In today's beer world haze is much more acceptable than it used to be. Brewers may want to preserve all the flavors they can without stripping anything out through a filtration process. A little bit of yeast present will actually act to prevent oxidation and is not necessarily a bad thing in smaller packaging operations which tend to experience high air pick up. If your beers are meant to be served brilliantly clear you will need to stabilize and filter. If your customers do not expect a brilliantly clear beer but you do want some degree of clarity then you might be able to use finings to clarify out most of the yeast and chill haze prior to packaging and avoid sediment formations. There are a variety of products on the market available for this purpose, it is a low technology solution for basic physical stability issues. I would certainly recommend against using any kind of process that adversely affects the flavors that you want to sell. More important for hop led package beers is to invest in crown caps with liners that will not scalp the hop flavors from your beers. Consult your suppliers to see what they can offer.

​Q: I have a question for your blog about predicting dissolved oxygen levels. I am looking for an equation that will predict with reasonable accuracy the dissolved oxygen levels of wort using an inline aeration assembly with a lpm regulator on the oxygen tank. I have heard that anywhere from 4 to 6 lpm for 30 to 45 minutes with a 10bbl system with give about 8ppm dissolved oxygen, but this range is far to large. Lets assume that my oxygen stone is clean, I run at 4lpm for 30 minutes into 10bbls of wort at 11 degrees celsius. Is there an equation out there that will take into account these components and provides with a somewhat accurate prediction for DO levels? Any help would be greatly appreciated!

A: Correct wort aeration is critical for yeast health and performance. A fairly easy way to gauge O2 absorption to your flow meter is to simply put the O2 tank onto a scale and observe the net weight used for a typical wort run off. Assuming the O2 is completely absorbed you can take the weight in milligrams and divide it by the total liters of wort run. Compare this figure to the flow rate in liters per minute on your flowmeter and make the necessary adjustments to your aeration flow. The target should be about 8-10 ppm (mg/L) dissolved oxygen. For 10 bbls of wort (1,172 liters) you should be adding 9.4to 12 grams of oxygen to achieve 8- 10 mg/L. Make sure your aeration stone is kept clean, clean it regularly with a causitc-oxidizer solution and soak it in acid every once in a while to dissolve mineral deposits.

​Q: We use an infusion mashing vessel with a deep 3 foot bed. We are having problems running off wheat beers with more than 20% wheat grist. What options exist to make this easier?

A: Infusion mash tuns were designed to make all-barley malt mashes in British brewing. The barley used is normally very well modified and crushed more coarsely than a typical North American malt to form the grist. The coarse grist including the non-soluble husk and gentle infusion mashing are able to form a permeable mash bed that is relatively deep and does not require rakes to facilitate run off. Wheat (and rye) malt does not have a husk and the grain is usually not very well modified meaning that it not only does not help in forming a filter bed and has greater amounts of beta glucan material that will increase the viscosity of the wort. Beta glucan in malt is the cell wall material that encases the starch granules in the barley grain, it is partially broken down during malting in the germination process. Large amounts of wheat and rye in the grist will tend to decrease permeability and yield run off problems. There are two options commonly used to alleviate the issue of slow run-offs with high wheat or rye malt grists. One is to add rice hulls to the grist which will help in forming a more permeable mash bed but this will not decrease the beta glucan present so it only offers a partial solution. The other option, which can be used in conjunction with rice hulls on on its own, is to use a glucanase enzyme that will break down the remnant beta-glucan material in the mash. By breaking down this material the viscosity of the wort will decrease significantly and the run-off is much easier even with higher wheat and rye grists. The enzyme is deactivated during the subsequent kettle boil. b Either way look for barley malt specifications limiting the barley beta glucan levels to less than 100 ppm.

A: Once wort is fermented into beer it is a hostile environment for most micro-organisms to grow very well especially (and fortunately) pathogens which can caused infections in humans. The primary limitations to growth of disease causing bacteria like Salmonella and Clostridium are:• Low pH (under 4.6)• Anaerobic conditions (no oxygen)• High CO2 content (toxic)• Low temperatures (pathogens prefer warm body temperature)• Depletion of nutrients (the yeast have already digested most available carbohydrates and proteins)• Ethanol concentrations above 2.5% ABV• Hop acids (above 20 BU’s)

Published: 4/2/2014 5:35 PM

]]>i:0#.f|mbaamembershipprovider|kockert@mbaa.comMicrobiologyWed, 02 Apr 2014 22:36:47 GMThttp://www.mbaa.com/brewresources/brewblog/Lists/Posts/ViewPost.aspx?ID=33Cost of building a breweryhttp://www.mbaa.com/brewresources/brewblog/Lists/Posts/ViewPost.aspx?ID=32
Title: Cost of building a brewery

Body:

​Q: I was just wondering if there is a flat rate cost per hectolitre for building a brewery? I understand this would only be a guideline but a general figure would be helpful.

A: This is a much more complicated question than it sounds and you would need to pin down many more details in determining even a ballpark estimate, a few of which are:• How many hL per year production• Green or brown field, real estate and construction costs• New or used equipment• Level of automation• Packaging or draft only• Brewery pub attached• Level of regulatory issues

Sorry but there is no easy answer I can provide to you. I suggest you talk to people who have started breweries similar to what you are thinking of. Go to your local MBAA district meeting, there are many people there who might be able to help guide you.

​Q: Is there a quick easy test for gram positive or negative bacteria that does not use the gram staining procedure?

A: Most common beer spoilers are gram positive bacteria.If you see a bacterial colony growing on a petri dish you can use a quick test to screen it for a gram positive reaction.Place a loop of the colony onto a slide (using sterile technique) and place a drop of potassium hydroxide on the colony.Using the loop check to see if the colony appears “gooey” or not.A gooey consistency indicates a gram negative colony while a non-gooey consistency indicates a gram positive.Perform a proper gram stain to confirm this is a gram positive organism.

Q: What is the difference between “gauge pressure” (PSIG) and “absolute pressure” (PSIA)?

A: The atmospheric pressure at sea level is 14.67 pounds per square inch, this is essentially the pressure that gravity exerts on us and we don’t feel that pressure because it is what we normally experience in the closed system we call Earth.When you look at a pressure gauge you will see the applied pressure above the atmospheric pressure which is called gauge pressure and indicates the pressure inside a closed system such as a tank or line.If you want the total pressure on the system then you have to add the 14.67 psi to the gauge pressure and this is called “absolute pressure.”Absolute pressure is often used on steam tables.Another commonly used pressure measurement is “bar” which equals one atmosphere of pressure or 14.67 psig.

​Q: We are struggling to maintain the hop flavor and aroma in some of our packaged beers. We have found that filtration is the biggest stripper of hop flavor so we are working towards ways to reduce or eliminate DE filtration. That gets the beer in the bottle tasting great, but keeping it there is a problem. DO’s in the package are in the 50 ppb range. Cans taste better than bottles. Switched over to oxygen barrier crowns and will look at oxygen scavenging crowns despite the common belief that they strip hop oils. We think they would saturate quickly and the scavenging quality may more than offset that loss of oil.

A: "scalping" from crown liners is a major problem in keeping big hop flavor, I have heard that as much as 80% of hop aroma disappears in the first 60 days in bottled beers. I know many IPA's in the bottle that lose their great hop aroma quickly and are never as good as on draft. I suggest going to your crown company or other suppliers and talking to them about scalp resistant liners.